Vises that mount on a machine tool support a workpiece in a secure position while being acted upon by the machine. They generally have flat opposing faces called jaws that are brought toward one another with the workpiece in between with sufficient force to resist the forces of machining on the workpiece. The jaws are generally provided with means for attaching a machinable jaw plate to their face. The plate is machined to fit the contour of the work piece so that the vise can better hold a workpiece that is not effectively held by parallel flat faces. The machinist generally starts with a block of aluminum. It is then cut to size, and holes bored to correspond to the vise jaw bolt holes. The exposed faces are then machined to conform to workpiece surfaces that are to be held. Preparing the plates for machining is labor intensive, requiring the services of the skilled machinist at the shop, and the plates may not be held securely by the bolts alone. U.S. Pat. No. 994,240 issued Jun. 6, 1911 to Bingham teaches a tongue projecting from the front face of a vise jaw more than half way down the jaw face, and a removable jaw of a machinable material to be bolted onto the tongue. The plate has a slot milled in its face to receive the tongue so that the top and bottom of the slot are held securely by the top and bottom of the tongue.